1. Field of the Invention
The invention relates to a conveyor belt with a main plane and a longitudinal direction defined in this main plane and corresponding to the transporting direction of the conveyor belt, which conveyor belt comprises a number of coupling elements, each comprising:
two links which are each present on a side of a coupling element and which are each coupled to a corresponding link of a longitudinally adjacent coupling element;
a pin which extends at least over a straight central part in transverse direction relative to the coupling elements and is connected to the outer two links, and which has a part which protrudes beyond the outer surface of a link and is bent through at least 90°;
at least one of which outer links has a general U-shape, which U extends in the main plane of the conveyor belt and has a form widening toward the open end, such that the relatively narrow zone at the closed end fits into the relatively wide zone at the open end of an adjacent link;
each of which pins extends in a substantially fixed relative position through two first continuous holes in the end zones of the legs of the U of the link, and
without fixed relative position through two second continuous holes in the legs at the position of the relatively narrow zone of a preceding link, which second holes are embodied as slotted holes extending in longitudinal direction;
such that two mutually adjacent coupling elements can be moved out of the main plane and are mutually rotatable in the main plane.
2. Description of the Related Art
Such a conveyor belt is for instance known from EP-A-0 377 775.
This known conveyor belt comprises a number of pins which are bent through 180° on either side. The inward directed free ends are inserted into respective holes of corresponding links. In this prior art conveyor belt the straight central part of the pin is guided over the links and free ends bent through 180° are inserted into said continuous holes in the end zones of the legs of the U of the link. In this known conveyor belt the pin is welded fixedly onto the link.
A known conveyor belt comprises plastic or metal pins which extend substantially in transverse direction and are connected to the plastic or metal links. One or more metal or plastic carriers can be mounted between the links for the purpose of carrying products. Such a filling can for instance consist of spiral wire, plastic modules or the like. Such conveyor belts and carriers are generally known.
In respect of the two degrees of freedom of rotation, i.e. the pivotability out of the main plane and the rotatability in the main plane, conveyor belts of this type, which are also referred to as spiral belts, are applied mainly in so-called spiral towers, in which the conveyor belt is transported respectively upward and downward in the manner of a helix, whereby a great belt length is realized on a relatively small floor area. The conveyor belt is here trained around a driven vertical drum. The spiral belt is driven by friction between the vertical drum and the side surfaces of the spiral belt. It is important in this respect that the side surfaces of the belt are finished such that they cannot hook into or onto the drum or damage the drum.
The metal conveyor belts of the stated type currently available commercially are all provided with welded connections between the pins and the links.